This application is related to U.S. Pat. application Ser. Nos. 08/192,072 a continuation of 07/720,259 entitled COMPUTER SYSTEM MANAGER now abandoned, 08/157,335 a continuation of 07/719,240 entitled INNATE BUS MONITORING SYSTEM FOR COMPUTER SYSTEM MANAGER, 07/720,258 entitled IN-BAND/OUT-OF-BAND ALERT DELIVERY SYSTEM, now abandoned 07/719,243 entitled REMOTE CONSOLE EMULATOR FOR COMPUTER SYSTEM MANAGER, and 07/719,394 entitled POWER SUPPLY FOR COMPUTER SYSTEM MANAGER, now U.S. Pat. No. 5,283,905 all of which were filed on Jun. 24, 1991, assigned to the assignee of the present invention and hereby incorporated by reference as if reproduced in their entirety.
This application is further related to co-pending U.S. patent application Serial Nos. 07/756,488, entitled NETWORK PROTOCOL FOR COMPUTER SYSTEM MANAGER, now U.S. Pat. No. 5,309,563; 07/757,066, entitled POWER SUPPLY FOR COMPUTER SYSTEM MANAGER, now U.S. Pat. No. 5,272,382; and 07/756,509 entitled ASYNCHRONOUS PROTOCOL FOR COMPUTER SYSTEM MANAGER, now U.S. Pat. No. 5,257,384, all of which were filed on even date herewith, assigned to the assignee of the present invention and hereby incorporated by reference as if reproduced in their entirety.
1. Field of the Invention
The present invention relates to remote console emulation systems and, more particularly, to means for rebooting the host within such systems.
2. Description of Related Art
In the past, digital data processing systems, or computers, were large and expensive systems including one or only a few central processor units connected to a main memory, mass storage such as disk and tape units, and input/output units such as printers, video display terminals, and telecommunications; links. Because of the cost of such systems, they typically supported a number of users, and a significant amount of design effort went into making them faster. However, as more parts of the computers were put into integrated circuit chips, including entire central processor units, the cost of computers declined dramatically, and so it became cost effective in many applications to devote a single computer to one or only a few users.
A benefit of having all users using a single large computer system is that data and programs may be shared among a number of users. This benefit can also be realized in an environment of smaller computers if they are linked together, for example, to form a distributed system. In a distributed system, the system is controlled by a host computer which provides services to remote consoles or satellite computers, such as data and programming sharing, and scheduling of resources such as printers and the like. In addition, the host may assist the remote consoles in booting, that is, in obtaining their operating systems when they (the remote consoles) initially begin operating. The operating system programs are programs which are used to control the remote systems, including transfers to other devices in the distributed systems. Of course, it is important for host computers also to be booted.
Emulation is well known to those skilled in the computer arts as the imitation of all or part of one computer system by another system so that, for example, the imitating computer system accepts the same data, executes the same programs, and achieves the same results as the imitated system.
Emulation has heretofore been used with respect to consoles. That is, secondary or remote consoles have been added to host systems and have been caused to operate by emulation of the host's primary console. Via such mechanisms, increased control over host systems can be exercised with relative efficiency and ease.
One aspect of effecting remote console control over host systems is causing booting of the host system to occur. Heretofore, network management packages have been developed that can boot systems, but the practical utility of such systems is low because a high degree of system operation is required to exercise the capability. For example, these packages require at least some software running in the host system in order to operate. This causes further shortcomings and deficiencies. The required host software must be appropriately tailored for the individual host with which it is to be used, which increases complexity and cost of development and installation, and decreases host performance. Additionally, because host running software is required for bootings, if the host fails, booting cannot be effected. Based on the foregoing, it is a shortcoming and deficiency of the prior art that remote booting systems have not heretofore operated independently of the host system and/or with very low system operation requirements.